Aromatic diamines as coupling components for the formation of photographic azine dyestuff images



Patented Feb. 27, 1951 STATES. TENT OFFICE AROMATIC DIARHNES AS COUPLINGCOM- PGNENTS FOR THE FURMATION OF PHO- TUGRAPHIC AZHNE DYESTUFF IMAGESDelaware N Drawing. Application March 18,1948, Serial No. 15,734

Claims.

The present invention relates to color photography and more particularlyto the production of azine dyestuff images by the color development ofexposed silver halide emulsion layers.

This application is a continuation-in-part of our application Serial No.577,134, filed February 9, 1945, entitled Preparation of Azine DyestufiImages, now abandoned.

One of the best known methods for the production of color images incolor photography involves the reaction of a color component with theoxidation products of a primary aromatic amino developer by whichdyestufi images are produced in situ with the silver image. Byeliminating the silver image associated with the dyestufi image byresort to a mild bleaching agent such as potassium ferricyanide, a puredyestuff image remains. This method, which was devised by Fischer and isdescribed in United States Patent No. 1,102,028, is commonly referred toin the art as the color-forming development method.

ihe color-forming components which are generally utilized by the art forreaction with the oxidation products of the primary aromatic aminodeveloper, are phenols, aromatic primary amines and compounds containinga reactive methylene roup such as acetoacetic acid derivatives,pyrazolones and the like. By the reaction between these compounds andsaid oxidation products, there are produced quinonimine or azo methinedyes. By a proper selection of the components used it is possible toform in the various layers of a multilayer film substractively coloreddyestufi images, to wit, yellow, magenta and cyan.

These color-forming components, in order to react effectively with theoxidation products of the developer, must contain a free couplingposition. In the phenols and aromatic amines this position is usuallypara to the phenolic hydroxy or amino group, and such position must beeither unsubstituted or if substituted, then by a substituent groupwhich is displaced during color-forming development. Such substituentsare the sulfonic. acid group, halogen such as chlorine, bromine and thelike, or the azo group. It is recognized in the literature that suchsubstituents even when in para position to the coupling directingphenolic hydroxyl or amino group do not impede the color developmentreaction because of the facility with which they are displaced to yieldan unsubstituted coupling position.

In the pyrazolones the free coupling position is occupied by the carbonatom of the reactive methylene group. Because of the tautomerizablenature of the keto gro'upof the pyrazolone, said carbon atom isconditioned for couplin with the oxidized primary amine of thedeveloper.

While it is relatively simple by the known method to produce thedyestuff images, the method is not always satisfactory for the reasonthat the quinonimine and azo-methine dyestuffs do not have optimumproperties as regards stability to light and to various chemicalreagents. Thus many of the dyes are acid-sensitive and fade or losetheir color values when subjected to the action of acidic materials. Thesame is true when the film is stored for long periods of time.

It has now been discovered that azine dyestuff images which are morestable than the quinonimine and azo methine dyestuff images can beformed by color-forming development while uti-' lizing the conventionalprimary aromatic amino developers if there be selected for thecoloriormin components aromatic compounds containing an amino group inthe 1-position and having a reactive coupling position para to the aminogroup, and in the 3-position a grouping capable of undergoing ringclosure with the intermediary azo methine or quinonimine to yield anazine dyestufi.

It is accordingly an object of this invention to produce azine dyestufiimages by color forming development.

It is a further object of this invention to produce azine dyestufiimages by the color development of a silver halide emulsion containingcolorforming components having particular substituents in ortho positionto the active coupling position.

It is a further object of this invention to provide silver halideemulsions containing c0lorforming components which when reacted with theoxidation products of a primary aromatic amino developer yield azinedyestuff images.

It is a further object of this invention to provide color developerscontaining a primary aromatie amino developer and a color-formingcomponent which upon reaction with the oxidation products of thedeveloper yield azine dyestuff images.

Other and further important objects of the invention will becomeapparent as the description proceeds.

Color-forming components which we have found will yield the azinedyestuff images upon reaction with the oxidation products oi? .a primaryaromatic amino developer and subsequent ring closure are as statedaromatic compounds containing in the lposition of the aryl ring an aminogroup which may be primary, secondary or l N l in which the numeral 3indicates the 3-position of the aromatic amino coupling components. Thesubstituents in the 3-position of such aromatic amines must therefore besuch as to contribute a nitrogen atom to the azine ring system and atthe same time have the ability to facilitate closure of the ring withthe elimination of certain atoms. We have ascertained that substituentswhich answer these prerequisites have the formula NI-IZ- wherein Z is anorganic atom grouping more negative than hydrogen (in the sense thisterm is employed in U. S. P. 2,378,169), and which is capable of beingsplit off with hydrogen during the ring closure operation.

It has been stressed that the grouping NHZ- must participate in theclosure of the ring in the system obtained by the reaction of thearomatic amino coupling component with the oxidation products of thedeveloper, or, in other words, with the intermediary quinonimine.Paraphrasing this, such substituent must not contain any grouping whichduring color development reacts in a Way to impede ring closure. Thismeans that Z must not contain a free coupling position for in that eventit is quite likely to react with the oxidized developer to yield astable system unamenable to ring closure. For instance, should Z containa phenolic hydroxyl group and in para position thereto a free couplingposition, the oxidized developer would quite likely couple in such freeposition producing a system which would preclude the desired ringclosure necessary for the formation of the azines.

The aromatic amines which we have found to be suitable for our purposein that they meet the requirements stressed above are of the followinggeneral formula:

NHZ

in which B is hydrogen or a hydrocarbon radical such as alkyl, 1. e.,methyl, ethyl, butyl and the like, aryl, i. e., phenyl, naphthyl and thelike, Z may be in which R is alkyl, such as methyl, ethyl, propyl,butyl, amyl, octyl, cetyl and the like, or aryl, such as phenyl,naphthyl and the like, or acylaminoaryl, such as acetylaminophenyl,butyrylaminophenyl, stearylaminophenyl and the like,

and X is hydrogen, alkyl, as above, or aromatic such as phenyl,diphenyl, naphthyl, nitrophenyl, chlorophenyl, alkoxyphenyl, i. e.,methoxyphenyl, ethoxyphenyl and the like, arylsulfonylaminophenyl, suchas benzsulfonylaminophenyl and the like, or a fused-on aryl, such asbenzo, sulfobenzo, naphtho and the like. As shown by the specificexamples given below, it is preferable where Y is arylamino that X be afused-on aryl.

Examples of compounds which fall within the above category and whichhave been found suitable for the production of the azine dyestuff imagesby color-forming development are the following:

3'-amino benzenesulfon-p-toluidide NHa H NSOz-O-CH;

1,3-dianilino-naphthalene-S-sulfonic acid N-octadecyLLS-di- (3-sulfoanilino) -8-naphthalene 3-cyanoamino-6-methyl dimethylaniline NEON3-carbetl1oxy amino-6-methy1 dimethylaniline 3-acetamldodiethylanlllnewz l) NHCOCH;

3-ethoxalylamido-G-methyldiethyluniline NHCO.CO.OC2H53'-aminomethanesulfonanilide NHBOQOHI3'-amino-4-stearamidobenzenesulfonanilide IIIHz 4,4'-di-(phenylsulfonamido -3-amin0biphenyl N02 NH:

NH-SOzR NH-SOzR Compounds in which the 1- and 3-positions aresubstituted by arylamino groups can be prepared by heating with anarylamine and an arylamine hydrochloride, for instance, aniline andaniline hydrochloride, a B-sulfoarylamine or a 3- sulfophenol. Thisreaction may be graphically represented as follows:

heated with RNH: and RNH2.HC] S 0 3H Alternatively, said compounds maybe produced by heating a 1.3-dihydric phenol with sodium sulfite andheating the resulting sulfite addition product with an arylaminehydrochloride such as aniline hydrochloride. This reaction may begraphically represented as follows:

(3H NH-R NazS O3( sulfite addi- ENE-H01 0H tzon product) fusion NH-RCompounds containing the cyano amino group may be obtained by reactingthe arylamine with cyanogen chloride. On the other hand, compoundscontaining a carbethoxy amino group (aryl urethanes) may be formed byreaction of a primary arylamine with, for example, ethyl chlorocarbonate in the presence of an acid-binding agent such as pyridine.

Compounds containing an acetamide group in 3-position are produced byreacting a primary arylamine with acetyl chloride. Compounds containingthe oxalyl amino group in 3-position are obtained by reacting a primaryarylamine with the mono-ethylester of oxalyl chloride or with ethyloxalate.

3 amino 4 stearoylamidobenzenesulfonanilide is obtained by reacting3-nitro-aniline with p-acetylaminobenzenesulfonyl chloride in thepresence of an acid-binding agent such as pyridine, treating theresulting product with an alkali to split off the acetyl group, heatingthe resulting compound with stearoyl chloride in the presence of anacid-binding agent such as pyridine, and reducing the product thusobtained in ethyl alcohol by means of hydrogen and a Raney nickelcatalyst. The sequence of steps involved may be illustrated as follows:

alkali NHSOF' NHCOCH3 NHSOr-ONH:

4,4 di (phenylsulfonamido) 3 aminobiphenyl is obtained by starting from3-nitrobenzidine, heating the same with benzenesulfonyl chloride in thepresence of an acid-binding agent and reducing the nitro group as above.

N-octadecyl 1,3 di (3 sulfoanilino) 8- naphthalene sulfonamide isobtained by treating 1.3 diamino naphthalene 8 sulfonic acid (Beilstein,vol. 14, p. 756) with acetic anhydride to block the amino groups. Theresulting compound is then subjected to the action of phosphoruspentachloride to convert the sulfo group to a sulfonyl chloride group.This product is 7 then heated with stearylamine in the presence of anacid acceptor to convert the sulfonyl chloride group to a sulfonamidegroup. By treatment in an aqueous alkaline solution, the blocked aminogroups are subjected to hydrolysis with regeneration of the primaryamino groups. The resulting product is then treated with metanilic acidaccording to the Bucherer reaction to give the desired end product.

The reaction by which the azine dyestufis are produced involves twoconversions which may take place spontaneously or in an observablesequence, the first involving the formation of a quinonimine dye and thesecond involving ring closure to produce the azine compound. The azinecompound so formed may be present as the anhydride of the free base.Upon acidification, the true azine salt is formed which possesses acharacteristically brilliant color.

The course of the reaction, in which it is pssible to observe definitesteps, may be illustrated by the reaction between the oxidation productsof para-amino dimethyl aniline and 3aminobenzenesulfon-p-toluidide. Thisreaction may proceed as follows:

NH; lfiIE CH CH -NSO'r NH.SO: H A l n It HzN /CH3 /CH:-z N N CH Bluequlnommine CH3 Hms-O I N +HX /C a N NHa (HERO CH3 Magenta salt It willbe observed that in this reaction the blue quinonimine dye is firstformed, which ring closes due to the presence of the sulfonamido groupin B-position to the azine anhydride. The latter by acidification isconverted into the azine salt which is characterized by a brillientmagenta color.

The invention may be carried into effect in various ways. One method ofrealizing the formation of the azine dyestuff images involves exposing asilver halide emulsion and subjecting it to the action of a primaryaromatic amino developer such as para-amino dimethyl aniline containingone of the aforesaid color-forming components or the silver halideemulsion may be exposed, developed to black-and-white and latersubjected to the action of such a developer. On the other hand, thecolor-forming component may be incorporated in the emulsion and afterexposure subjected to the action of a primary aromatic amino developer.In the latter case, it is advisable to employ the color formingcomponents in a form in which they are fast to diffusion in the gelatin.This result may be achieved by the following procedures outlined inUnited States Patents 2,186,852, 2,186,851, 2,- 186,849, 2,186,734,2,186,733, 2,186,732, 2,179,244,

and 2,303,928. Preferably, however, the color former is rendered fast todiffusion by including in the molecule thereof a radical having an alkylchain of 5 carbon atoms or more such as decyl, dodecyl, stearyl, oleylor the like radical. An example of a compound which has been renderedfast to diffusion by the inclusion of a long alkyl chain is given above.

In order to facilitate the incorporation of the color formers in thesilver halide emulsion or in the developer, the compounds may containsubstituents which increase the solubility of the compounds in aqueousor in alkaline solutions. Such groups are, for instance, sulfonic acidgroups, carboxylic acid groups, sulfonamide groups and hydroxy ethenoxyether groups. Example of a compound containing a water-solubilizinggroup, i. e., a sulfonic acid roup, has been given above. This group maybe replaced in the involved compound by a carboxylic acid or a hydroxyethenoxy ether group.

The following examples will serve to illustrate the invention but it isto be understood that the invention is not limited thereto.

Example I To 100 g. of a photographic silver halide emulsion is added0.5 g. of 1,3-di-anilino-naphthalene- 8-sulfonic acid-sodium salt. Theemulsion is then coated on a transparent film support and dried. Afterexposure the film is developed in a color-forming developer comprisingWater cc. 1000 Sodium sulfite g. 0.5 p-Diethylamino-aniline g. 2.5Sodium carbonate g. Potassium bromide g. 2.5

A silver plus dye image is formed. After removal of the silver bybleaching in potassium-ferricyanide solution and subsequent fixation, ablue dye image, stable to acid, remains.

Instead of developing the exposed film in a color-forming developer, itmay be developed to give a black-and-white negative image. The residualsilver halide is then exposed and color developed with the abovesolution. After removal of the silver by means of potassiumferricyanide, a positive blue dyestuff image is obtained.

Example 11 An exposed photographic silver bromide emulsion is developedin a color forming developer of the following composition:

70 Water cc 1000 Sodium sulfite g. 0.5 p-Diethylamino-aniline g. 2.5Sodium carbonate g. 70 Potassium bromide g. 2.5

3'-aminobenzenesulfon-p-toluidide g. 1

mersion into dilute hydrochloric acid, a brilliant magenta dye imageappears.

Example III To the developer solution of Example I there is added onegram per liter of B-acetamido-diethyl-aniline dissolved in methanol. Asilver bromide emulsion is exposed and developed in this solution. Afterremoval of the silver by means of potassium ferricyanide andacidification by the immersion of the emulsion into dilute hydrochloricacid, a magenta image is obtained.

Various modifications of the invention will occur to persons skilled inthe art and we therefore do not intend to be limited in the patentgranted except as necessitated by the appended claims.

We claim:

1. The process of producing azine dyestufl' images in a photographicsilver halide emulsion which comprises developing an exposed silverhalide emulsion in a primary aromatic amino developer in the presence ofan aromatic compound having the following formula:

NH-Z

where in A is an aromatic radical, B is a member selected from the classconsisting of hydrogen and hydrocarbon radicals, and Z is a radicalselected from the class consisting of R being a member of the classconsisting of alkyl, aryl and acylaminoaryl, said compound having a freecoupling position in the 4-position,

said radical Z having no free coupling position.

2. A photographic silver halide emulsion containing a color formingcomponent capable of producing an azine dyestuif image upon reactionwith the oxidation products of a primary aromatic amino developerconsisting of a compound having the following formula:

NH--Z wherein A is an aromatic radical, B is a member selected from theclass consisting of hydrogen and hydrocarbon radicals, and Z is aradical selected from the class consisting of B, being a member of theclass consisting of alkyl, aryl and acylaminoaryl, said compound havinga free coupling position in the 4-position, said radical Z having nofree coupling position.

3. A photographic developer for a developable image in a silver halideemulsion containing a primary aromatic amino developing substance and anaromatic compound capable of reacting with the oxidation productsthereof to produce an azine dyestuff, said aromatic compound having thefollowing formula:

wherein A is an aromatic radical, B is a member selected from the classconsisting of hydrogen and hydrocarbon radicals, and Z is a radicalselected from the class consisting of B being a member of the classconsisting of alkyl, aryl and acylaminoaryl, said compound having a freecoupling position in the 4-position, said radical Z having no freecoupling position.

4. The composition as defined in claim 2 wherein the color formingcomponent contains a group rendering it fast to difiusion in theemulsion.

5. The composition as defined in claim 3 Wherein the color formingcomponent contains a water solubilizing group.

6. The process of producing azine dyestuff images in a silver halideemulsion which comprises developing the emulsion with a primary aromaticamino developer in the presence of an aromatic amine having in the1-positionthe grouping grouping and said acylamino group having no freecoupling position.

7. The process as defined in claim 6 wherein B is alkyl.

8. The process of producing azine dyestufl images in a silver halideemulsion which comprises developing the emulsion with a primary aromaticamino developer in the presence of an aromatic amine having in the1-position the grouping B being selected from the class consisting ofhydrogen and hydrocarbon radicals, and in the 3 position an arylsulfonylamino group, said amine having a free coupling position para tothe grouping said grouping in the 3-position having no free couplingposition. v

9. The process of producing azine dyestufl images in a silver halideemulsion which com- B being selected from the class consisting ofhydrogen and hydrocarbon radicals, and in the 3- position an alkylsulfonylamino group, said amine having a free coupling position para tothe grouping and said grouping in the 3-position having no free couplingposition.

10. The process of producing azine dyestufi images in a silver halideemulsion which comprises developing the emulsion with a primary aromaticamino developer in the presence of an aromatic diamine having an arylamino group in the land VIZ-positions, the nitrogen atom of said arylamino group being directly linked to the ring, said aromatic diaminehaving a free coupling position in the 4-position and the grouping in3-position having no free coupling position.

11. A photographic silver halide emulsion containing a color-formingcomponent capable of reacting with the oxidation products of a primaryaromatic amino developer to produce an azine dye, said component beingan aromatic amine having in the 1-position the grouping B being selectedfrom the class consisting of hydrogen and hydrocarbon radicals and inthe 3- position and acylated amino group, the nitrogen atom of which isdirectly linked to the ring, said aromatic amine having a free couplingposition in the 4-position and said grouping in the 3- position havingno free coupling position.

12. A photographic silver halide emulsion as defined in claim 11 inwhich the amino group in the l-position of the aromatic amine is adialkylamino group.

13. A photographic silver halide emulsion as defined in claim 11 whereinthe acylated amino group in the 3-position is an aryl sulfonylaminogroup.

14. A photographic silver halide emulsion as defined in claim 11 inwhich the acylamino group in 3-position is an alkyl sulfonylamino group.

15. A photographic silver halide emulsion con taining a color formingcomponent capable of reacting with the oxidation products of a primaryaromatic amino developer to produce an azine dye, said component beingan aromatic diamine having in the 1- and 3-positions an arylamino group,the nitrogen atom of which is directly linked to the ring, said aromaticamine having a free coupling position in the 4-position, and said groupin the 3-position having no free coupling position.

16. A photographic color-forming developer for .a developable image in asilver halide emulsion comprising a primary aromatic amino developingagent and a color forming component capable of reacting with theoxidation products thereof to produce an azine dye, said component beingan aromatic amine having in the 1-position the grouping wherein B isselected from the class consisting of hydrogen and hydrocarbon radicals,and having in the 3-position an acylated amino group, the nitrogen atomof which is directly linked to the ring, said aromatic amine having afree coupling position in the 4-position and said grouping in the3-position having no free coupling position.

17. A photographic color forming developer for a developable image in asilver halide emulsion containing an aromatic amine as the developingagent and a color forming component capable of reacting with theoxidation products of such amine to produce an azine dye, said componentbeing an aromatic diamine having in the 1- and Z-positions an arylaminogroup, the nitrogen atom of which is directly linked to the ring, saidaromatic diamine having a free coupling position in the 4-position andsaid group in the 3-position having no free coupling position.

18. A photographic silver halide emulsion containing a color formingcomponent capable of reacting with the oxidation products of a primaryaromatic amino developer to produce an azine dye, said component being1.3-di-anilino naphthalene-S-sulfonic acid.

19. A photographic color forming developer for a developable image in asilver halide emulsion containing a primary aromatic amine as thedeveloping agent and a color forming component capable of reacting withthe oxidation products of said amine to produce an azine dye, saidcomponent being 3-amino benzene sulfon-p-toluidide.

20. A. photographic color forming developer for a developable image in asilver halide emulsion containing a primary aromatic amine as thedeveloping agent and a color forming component capable of reacting withthe oxidation products thereof to produce an azine dye, said componentbeing 3-acetamidodiethyl aniline.

VVILLY A. SCHMIDT. JOSEPH A. SPRUNG.

REFERENCES CKTED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

1. THE PROCESS OF PRODUCING AXINE DYESTUFF IMAGES IN A PHOTOGRAPHICSILVER HALIDE EMULSION WHICH COMPRISES DEVELOPING AN EXPOSED SILVERHALID EMULSION IN A PRIMARY AROMATIC AMINO DEVELOPER IN THE PRESENCE OFAN AROMATIC COMPOUND HAVING THE FOLLOWING FORMULA: